How do seismic accelerations work with foundations / PY curves / soil springs?
Category: Structural dynamics
Problem
Earthquake simulations require the application of a seismic acceleration time history to the turbine support structure. How does this interact with any foundation soil springs that are used in the model?
Solution
BLADED's seismic model imposes a prescribed aceleration at all the foundation nodes. Where a non-rigid foundation is defined at a node, the acceleration is applied to the "ground" at one end of the theoretical soil spring, not to the tower node at the other end. If we simplify to one DoF and imagine it as a literal spring, it would look something like this:
If using rigid foundations (no soil spring), the accelerations would be applied directly to the foundation nodes.
If using rigid foundations (no soil spring), the accelerations would be applied directly to the foundation nodes.
Keywords earthquake; seismic; P-Y curves; soil springs; foundations; acceleration